Grinding wheel dresser



Oct. 18, 1949.

Filed May 8, 1945 M. F. PORCELLO GRINDING WHEEL DRESSER 3 SheetLs-Sheet 1 INVENTOR M.F.P0rcell0 ORNEY Oct. 18, 1949. M. F. PORCELLO 2,485,311

GRI ND ING WHEEL DRES SER Filed May s, 1945 s Sheets-Sheet 2' INVENTOR M.F. orce'Ho Oct. 18, 1949. M. F. PORCELLO GRINDING WHEEL DRESSER 3 Sheets-Sheet 3 Filed' May 8 1945 INVENTOR M. FPorcel l'o KQ GR NEY Patented Oct. 18, 1949 GRINDING WHEEL DRESSER Morris F. Porcello, Battle Creek, Mich., assignor of forty per cent to Lynn W. Bishop, Battle Creek, Mich.

Application May 8, 1945, Serial .No. 592,603

5 Claims.

The present invention relates broadly to devices for dressing grinding wheels, and in its specific phases to an apparatus for use in forming or truing a radius or curved face on the periphery of a grinding wheel.

In the past the forming or truing of a radius on the periphery of a grinding wheel has involved cut and try hand procedures with or without a template, or the use of low accuracy or crude apparatus, or highly complex apparatus so slow and cumbersome that it is unsuitable for high production work. It was a knowledge of those difficulties and shortcomings, based on actual experience, which led to the discovery and development of the present invention.

Accordingly among the objects of the present inventionis the provision of a simple and thoroughly practical device for curved face dressing of the grinding wheel of a grinding machine.

Another object is to provide a grinding wheel dressing device for producing curved profiles, wherein the device is quickly mountable, simple to use, and readily demountable from the grinding machine so as to use relatively little time for the whole dressing operation.

Another object is to provide an improved dressing device in which the diamond dresser is moved back and forth manually in a predetermined curved path.

Another object is to provide a highly accurate and stabilized apparatus for dressing a curved or arcuate surface on the periphery of the grinding wheel of a-grinding machine.

Another object is to provide a grinding wheel dressing device which is mountable on the grinding machine in the place of the workpiece.

A further object is to provide a grinding wheel" dressing device which is readily adjustable for dressing the periphery of the grinding wheel to various radii.

A further object is to provide an apparatus suitable for the dressing of a radius on the periphery of the grinding wheel of a grinding machine having centers for holding the workpiece to be ground.

A still further object is to provide a highly simplified, quick acting, curved profile grinding wheel dressing apparatus adapted to be readily operated even by an operator having little training in the curved profile grinding wheel dressing art.

Still further objects and advantages will appear as the description proceeds.

To the accomplishment of the foregoing and related ends, the invention, then, consists of the means hereinafter fully described and particularly pointed out in the claims, the annexed drawings and the following description setting forth in detail certain means for carrying out the invention, such disclosed means illustrating, however, but several of various Ways in which the principle of the invention may be used.

In the annexed drawings:

Figure 1 shows a plan view of a preferred form of the present invention.

Figure 2 shows a front elevation of the assembly illustrated in Figure 1.

Figure 3 shows a left end elevation of the assembly illustrated in Figure 1.

Figure 4 shows a sectional view taken along line 44 of Figure 1 looking in the direction of the arrows.

Figure 5 shows a sectional view of a carrier member taken along line 55 of Figure 1 looking in the direction of the arrows.

Figure 6 shows a modified form of the apparatus of Figure 1 arranged for dressing the right hand edge of the periphery of a grinding wheel.

Figure 7 shows a modified form of the present invention which is adapted for dressing a curved profile on either or both sides of the periphery'of a grinding wheel.

For convenience of setting forth the present invention, it will be described in terms of an apparatus mountable upon a grinding machine adapted for grinding the curved under face of the head portion of a valve. The grinding wheel dressing apparatus, however, is not limited to use on that specific form of grinding machine since the principle involved is broadly usable on many types of apparatus, and especially those where the workpiece to be ground is mounted between centers, or a center and a chuck type means.

Referring more particularly to Figure 1 of the drawing, l indicates a fragmentary portion of a grinding wheel to be dressed by means of the apparatus of the present invention. The Wheel dressing assembly 2, in preferred form, comprises a base member 3 on which are mountedinner and outer guide ribs 4 and 5, Figure 4, which are machined to a uniform arc with parallel equally spaced faces. Mounted in the channel between the inner and outer guide ribs is a closely fitting slide member 6. Joined to the upper face of the guide ribs are inwardly extending inner and outer plates 1 and 8 which are fastened in place by means of screws 9, or the equivalent. Those plates in turn are machined so as to have their adjacent edges substantially equally spaced. Guide ribs 4 and 5, instead of having vertical in- 55 ner faces, may tilt inward to form ways, and

This dressing tool may be locked in place in con-" ventional manner, for instance by means era set screw l 3.

A removable gage l4, Figure 2,'with depending end l5 and scale I6, is arranged to be passed through the upper opening of carrier member 0,

and when adjusted in place,=it-rnaybdlockedagainst further movement by means of set screw H. The apparatus is set at the desired radius before this set screw is tightened, and then when the dressing tool I I is passed through itsopening in carrier member ID; it can be extended until it contacts the inner face of depending end l5, which acts'as a backstop. Screw' l3 can then be tightened to" lock dressing tool II in place; following which set screw I! may be loosened and gage l4 removed thus leaving the dressing tool in positionfo'r use as will be hereinafter explained.

Fastened in conventional manner, for instance by meansofscrews 48-, to'the under face of base member 3, are a pair of mounting members i8 and-19 which are preferably U-shaped and provided with a plurality of-grooves- 20 to facilitate adjustment of the assembly to different heights for dressing purposes. Set screws H are Placed opposite grooves 20, Figure 3, so that the supporting-member 22' may be gripped in place in either groove to meet the grinding wheel dressing'requirements.

Where the grinding machine isadapted for dressing th'e'underface of valve heads, the-conven-ient type'of supporting member 22 is a valve ofrthesame'size asis to-be ground on the machine. The tail stock 23, Figurel, and headstock 243th that case will be equipped to shift directly from the grinding of valves tothe mounting of the grinding wheel dressing assembly, andvice versa. Iniorderto makethe valve grinding machineimorez flexibleas to valve sizes, it isipreferable to -have. a tapered chuck-like member 25 adapted to fit a correspondinglytapered opening inithe head.stock.- The head of chuck-like mem- 1361 125, inturn, may have an outwardly tapering hollow "space therein adapted toreceive a reducingsadaptor 26 which in turn is hollow and outwardly tapered at its free end-so astoreceive and hold the head of a valve imposition concentric withthe rotatable portion of the head stock. hThiS makessthe -machine fiexible'in use since the reducing adaptor may be quickly removed or changed to other sizes with little delay in the operation of the machine.

In order tomake the apparatus relatively rigid in-.use it is preferably provided with a pair. ofsupporting members, one. of which, as is typically shown in Figure 3, consists of a depending-holder 21' having flanges 28 in its upper end suitably drilledto receive cap screws29 which threaded-1y engage base member 3. Dependingholder 21 is angularly drilled for the slidable reception of supporting rod-30lwhich can beadjusted endwise so that its lower end rests on the grinding machine, followingwhich set screw 3lcan be tightened to holdthesupporting rod in place. Under actual operating conditions member 30,"after being adjusted and locked in place, acts'toprevent the assembly from rotating in a counterclockwise direction about supporting member 22, as viewed in Figure 3. The other supporting member consists of a bar 32 which may be fastened in conventional manner to base member 3, for instance by means of cap screws 33 passing through an extending wing 34 which is preferably a portionof base member 3. T The freeend of bar 32 may be vertically drilled and threaded for the reception of an adjusting screw 35. Bar 32 is not only made relatively rigid but sufficiently long--to-reach to an adequate supporting spot against which screw 35 can be tightened to prevent-the apparatus from moving in clockwise directiomasviewed in Figure 3.

Some types of grinding machines have the head and tail-:stock mounted on a table which may be moved both endwise and crosswise of the'machine while the grinding wheel rotates in fixed location. On other machines the opposite istruep-in' that the head andtail stock are: used to-fixedly holdthe article to-be ground, while the grinding wheel is ::movable both endwise and crosswise of the machine. The present invention is adapted for use on either of these "types of machines.

In order to make the apparatus capable of very accurately dressingza grinding wheel, the slide member 6, Figures 4 and15,'fits the channel between inner and outer :guide ribs' l and- 5 with-a very close tolerance, and in order to keep grit, or other foreign matter, from getting between slide member 6, base member 3,-and guide ribs 4 and 5, xfelt wiper pads36- and- 31 are mounted on the ends of slide member 6 and held in placeby means of retainer plates 38 and 39, whichv inturn are fastened to slide membert by means of screws 40 and li. In order to keep grit, or other foreign matter, from working its way between .thesliding parts from the .top of the assembly, same may be providedwith felt pads42 and 43 held in place by retainer plates 44 and 45, which in turn are held on slide member 5 by means of screws 48 and. .The -felt pads are preferably'saturated with grease or oil so as to automatically lubricate thepath of travel of slide member 6 Whilepermitting a tight sliding fit between the felt and the adjacent surfaces in manner permitting the wiping of foreign matter out of the Way.

The assemblytypically illustrated in" Figures 1, 2, and 3 is primarily designed for rounding the left hand portion of the periphery of grinding wheel 1. If the machine has been grinding the radius on the under side of a head of 'a' valve and the profile of the grinding wheel I has gradually worn out of shape or near to the outer tolerance limits, the valve can be removed and the'present invention, which is preferably supported on a like size valve, quickly slipped in place, the diamond dressing tool ll adjusted to the desired radius and then the grinding wheeland'wheel dressing assembly moved relative to each other, with the grinding wheel still 'runninguntil they are in dressing position, whereupon carrier'member 10 may be gripped by the operatorand slid back and forth in its arcuate path onbase-member'3. This will move the diamond-point l2 of diamond dressing tool II in the proper arc and will 'cause the dressing of the edge of the wheel to take place as the two'are brought closer'and closer together in prescribed position."

In actual operation supporting rod 30 will be adjusted the first time it is used on a particular machine, and after having been lockedin place, it 'will normally remain them each time the 'tool is usedonthe same grinding machine." The'nor'- mal adjustments of the assembly will then be taken care of by means of adjusting screw 35. After installing the dressing assembly, the dressing of the grinding wheel I takes but a few minutes, whereupon the assembly can be removed from the machine which is still all set up and adjusted for immediate insertion of a valve and the starting of grinding the radius on the under face of the valve head.

While in Figure l the dressing of the periphery and the left hand edge of the grinding wheel 1 is shown, the present invention is not limited to that specific apparatus. Figure 6, for instance, shows a like apparatus of the type suited for dressing the periphery and right hand edge of a grinding wheel I. This figure also shows the modification wherein the member to be ground is mounted between a pair of centers 23 and the diamond dressing assembly is likewise mounted on a member of substantially like size permitting the assembly to be quickly mounted or removed as desired.

Another form of the present invention, as shown in Figure 7, utilizes a horse shoe shaped assembly, preferably mounted on a workpiece as before, and adapted for the diamond dressing of a grinding wheel on its periphery including both of its side edges.

It is thus to be seen that the device of the present invention is quickly mountable and demount- I explained, change being made as regards themechanism herein disclosed, provided the means stated by any of the following claims or the equivalent of such stated means be employed.

I therefore particularly point out and distinctly claim as my invention:

1. In a grinding machine for grinding the curved under face of the head portion of a valve member, and having a headstock and a tailstock for supporting the member to be ground, the combination with such headstock and tailstock,

of a member to be ground extending from said headstock to said tailstock and supported by same, a dressing device having means mounting said device on said member, said dressing device comprising means thereon to mount a dressing tool for movement in an arcuate path relatively to the grinding wheel, and means supplementing the mounting of said dressing device by said member and preventing turning of the device on the axis passing through said member, headstock and tailstock.

2. In a grinding machine for grinding the curved under face of the head portion of a valve member, and having a headstock and a tailstock for supporting the member to be ground, the combination with such headstock and tailstock,

of a member to be ground extending from said headstock to said tailstock and supported by same, a dressing device, means joined to said dressing device for mounting same at various elevations on said member, said dressing device comprising means thereon to mount a dressing tool for movement in an arcuate path relatively to the grinding wheel, and means supplementing the mounting of said dressing device by said member and preventing turning of the device on the axis passing through said member, headstock and tailstock.

3. In a grinding machine for grinding the curved under face of the head portion of a valve member, and having a headstock and a tailstock for supporting the member to be ground, the combination with such headstock and tailstock, of a member to be ground, a dressing device having means mounting said device on said member, said dressing device comprising means thereon to mount a dressing tool for movement in an arcuate path relatively to the grinding wheel, supporting means on one side of the axis of said headstock and tailstock for support on the grinding machine, and a supporting means on the device on the other side of said axis extending laterally beyond the adjacent end of said device for support on the grinding machine in spaced relation to the latter end.

4. In a grinding machine for grinding the curved under face of the head portion of a valve member, and having a headstock and a tailstock for supporting the member to be ground, the combination with said headstock and tailstock, of a member to be ground, a dressing device having bracket means depending therefrom mounting said device on said member with the ends of the member projecting beyond the bracket means, said dressing device comprising means to mount a dressing tool for movement in an arcuate path relatively to the grinding wheel, supporting means on one side of the axis of said headstock and tailstock adjustable as to height for support on the grinding machine, and a supporting means on the device on the other side of said axis extending laterally beyond the adjacent end of said device for support on the grinding machine in spaced relation to the latter end.

5. In a grinding machine according to claim 1, wherein the means to mount the dressing tool has an opening therein parallel to the axis of said tool and above said tool, a gage having a rod disposed in said opening and provided with a backstop extending angularly therefrom in front of the tool, and means to secure the gage in the latter position.

MORRIS F. PORCELLO.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

